syzbot


INFO: task hung in debugfs_remove

Status: auto-closed as invalid on 2019/07/10 16:36
Reported-by: syzbot+b2b116b5b8cd771af754@syzkaller.appspotmail.com
First crash: 1979d, last: 1979d

Sample crash report:
[30644]     0 30644    17601     8453      25       4        0             0 syz-executor2
[30649]     0 30649    17601     8229      24       3        0             0 syz-executor2
[30660]     0 30660    17601     8229      24       3        0             0 syz-executor2
[30687]     0 30687    17601     8229      24       3        0             0 syz-executor2
[30690]     0 30690    17601     8453      25       4        0             0 syz-executor2
INFO: task kworker/0:0:13059 blocked for more than 140 seconds.
[30702]     0 30702    17601     8229      24       3        0             0 syz-executor2
[30707]     0 30707    17601     8228      23       3        0             0 syz-executor2
      Not tainted 4.14.92+ #5
[30716]     0 30716    17601     8229      24       3        0             0 syz-executor2
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[30724]     0 30724    17601     8229      24       3        0             0 syz-executor2
kworker/0:0     D25280 13059      2 0x80000000
[30730]     0 30730    17601     8229      24       3        0             0 syz-executor2
Workqueue: events delayed_fput
[30748]     0 30748    17667    12554      32       4        0             0 syz-executor3
[30756]     0 30756    17601     8229      24       3        0             0 syz-executor2
[30771]     0 30771    17601     8228      23       3        0             0 syz-executor2
[30783]     0 30783    17601     8229      24       3        0             0 syz-executor2
[30796]     0 30796    17601     8229      24       3        0             0 syz-executor2
[30816]     0 30816    17601     8229      24       3        0             0 syz-executor2
[30823]     0 30823    17601     8229      24       3        0             0 syz-executor2
Call Trace:
[30830]     0 30830    17601     8229      24       3        0             0 syz-executor2
[30831]     0 30831    17601     8229      24       3        0             0 syz-executor2
[30839]     0 30839    17601     8229      24       3        0             0 syz-executor2
[30858]     0 30858    17601     8229      24       3        0             0 syz-executor2
[30861]     0 30861    17667    12554      32       4        0             0 syz-executor3
[30865]     0 30865    17601     8229      24       3        0             0 syz-executor2
 schedule+0x92/0x1c0 kernel/sched/core.c:3490
[30878]     0 30878    17601     8229      24       3        0             0 syz-executor2
 schedule_timeout+0x736/0xe80 kernel/time/timer.c:1721
[30885]     0 30885    17601     8229      24       3        0             0 syz-executor2
[30897]     0 30897    17667    12554      32       4        0             0 syz-executor3
[30901]     0 30901    17601     8229      24       3        0             0 syz-executor2
[30922]     0 30922    17667    12554      32       4        0             0 syz-executor3
[30925]     0 30925    17601     8230      24       3        0             0 syz-executor1
 do_wait_for_common kernel/sched/completion.c:91 [inline]
 __wait_for_common kernel/sched/completion.c:112 [inline]
 wait_for_common+0x29c/0x470 kernel/sched/completion.c:123
[30929]     0 30929    17634     8477      25       4        0             0 syz-executor1
[30941]     0 30941    17601     8230      24       3        0             0 syz-executor1
[30945]     0 30945    17634     8232      24       3        0             0 syz-executor1
[30951]     0 30951    17601     8230      24       3        0             0 syz-executor1
[30954]     0 30954    17634     8232      24       3        0             0 syz-executor1
[30968]     0 30968    17601     8230      24       3        0             0 syz-executor1
[30969]     0 30969    17634     8477      25       4        0             0 syz-executor1
[30972]     0 30972    17634     8232      24       3        0             0 syz-executor1
[30981]     0 30981    17634     8456      25       4        0          1000 /group.stat
[30990]     0 30990    17667    12554      32       4        0             0 syz-executor3
 __synchronize_srcu+0x12a/0x210 kernel/rcu/srcutree.c:898
[30993]     0 30993    17601     8230      24       3        0             0 syz-executor1
[30994]     0 30994    17634     8477      25       4        0             0 syz-executor1
[30998]     0 30998    17634     8232      24       3        0             0 syz-executor1
[31009]     0 31009    17601     8230      24       3        0             0 syz-executor1
[31012]     0 31012    17634     8232      24       3        0             0 syz-executor1
 debugfs_remove fs/debugfs/inode.c:664 [inline]
 debugfs_remove+0xc7/0x110 fs/debugfs/inode.c:649
[31027]     0 31027    17667    12552      32       4        0             0 syz-executor2
[31029]     0 31029    17667    12554      32       4        0             0 syz-executor3
[31030]     0 31030    17601     8230      24       3        0             0 syz-executor1
[31033]     0 31033    17634     8477      25       4        0             0 syz-executor1
[31035]     0 31035    17634     8232      24       3        0             0 syz-executor1
 binder_release+0x59/0x80 drivers/android/binder.c:5074
[31043]     0 31043    17601     8230      24       3        0             0 syz-executor1
 __fput+0x25e/0x700 fs/file_table.c:210
[31044]     0 31044    17634     8477      25       4        0             0 syz-executor1
[31049]     0 31049    17634     8232      24       3        0             0 syz-executor1
[31057]     0 31057    17634     8477      25       4        0             0 syz-executor1
 delayed_fput+0x45/0x60 fs/file_table.c:239
[31067]     0 31067    17667    12552      32       4        0             0 syz-executor2
[31073]     0 31073    17667    12554      32       4        0             0 syz-executor3
 process_one_work+0x7c6/0x14e0 kernel/workqueue.c:2114
[31074]     0 31074    17601     8230      24       3        0             0 syz-executor1
[31077]     0 31077    17634     8477      25       4        0             0 syz-executor1
 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2248
[31079]     0 31079    17634     8232      24       3        0             0 syz-executor1
[31087]     0 31087    17601     8230      24       3        0             0 syz-executor1
[31089]     0 31089    17634     8477      25       4        0             0 syz-executor1
 kthread+0x310/0x420 kernel/kthread.c:232
[31094]     0 31094    17634     8232      24       3        0             0 syz-executor1
[31104]     0 31104    17601     8230      24       3        0             0 syz-executor1
[31111]     0 31111    17667     8234      24       3        0             0 syz-executor1
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
[31119]     0 31119    17634     8232      24       3        0             0 syz-executor1

Showing all locks held in the system:
[31121]     0 31121    17634     8477      25       4        0             0 syz-executor1
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffffae5ff9cc>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541
[31123]     0 31123    17634     8456      25       4        0          1000 /group.stat
2 locks held by rsyslogd/1629:
 #0:  (&mm->mmap_sem){++++}, at: [<ffffffffae4b43e1>] __do_page_fault+0x271/0xb80 arch/x86/mm/fault.c:1354
[31141]     0 31141    17667    12554      32       4        0             0 syz-executor3
 #1:  (&ei->i_mmap_sem){++++}, at: [<ffffffffaeb5e19c>] ext4_filemap_fault+0x7c/0xb0 fs/ext4/inode.c:6183
[31144]     0 31144    17601     8230      24       3        0             0 syz-executor1
2 locks held by getty/1757:
[31147]     0 31147    17634     8232      24       3        0             0 syz-executor1
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffffaf137492>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:275
[31154]     0 31154    17601     8230      24       3        0             0 syz-executor1
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffffaf1328b7>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
[31159]     0 31159    17634     8236      25       3        0             0 syz-executor2
2 locks held by syz-fuzzer/1782:
 #0:  (&mm->mmap_sem){++++}, at: [<ffffffffae4b43e1>] __do_page_fault+0x271/0xb80 arch/x86/mm/fault.c:1354
 #1:  (&ei->i_mmap_sem){++++}
[31160]     0 31160    17634     8232      24       3        0             0 syz-executor1
, at: [<ffffffffaeb5e19c>] ext4_filemap_fault+0x7c/0xb0 fs/ext4/inode.c:6183
[31169]     0 31169    17601     8230      24       3        0             0 syz-executor1
2 locks held by syz-fuzzer/1784:
 #0:  (&mm->mmap_sem){++++}, at: [<ffffffffae4b43e1>] __do_page_fault+0x271/0xb80 arch/x86/mm/fault.c:1354
 #1:  (&ei->i_mmap_sem){++++}, at: [<ffffffffaeb5e19c>] ext4_filemap_fault+0x7c/0xb0 fs/ext4/inode.c:6183
[31175]     0 31175    17667     8234      24       3        0             0 syz-executor1
2 locks held by syz-fuzzer/1792:
 #0:  (&mm->mmap_sem){++++}, at: [<ffffffffae4b43e1>] __do_page_fault+0x271/0xb80 arch/x86/mm/fault.c:1354
 #1:  (&ei->i_mmap_sem){++++}, at: [<ffffffffaeb5e19c>] ext4_filemap_fault+0x7c/0xb0 fs/ext4/inode.c:6183
1 lock held by syz-executor0/2702:
[31185]     0 31185    17634     8456      25       4        0          1000 /group.stat
 #0:  (&sig->cred_guard_mutex){+.+.}, at: [<ffffffffae96bee1>] prepare_bprm_creds+0x51/0x110 fs/exec.c:1389
[31197]     0 31197    17667    12554      32       4        0             0 syz-executor3
2 locks held by kworker/0:0/13059:
 #0:  ("events"){+.+.}, at: [<ffffffffae527d65>] process_one_work+0x6e5/0x14e0 kernel/workqueue.c:2085
 #1:  ((delayed_fput_work).work){+.+.}, at: [<ffffffffae527d9b>] process_one_work+0x71b/0x14e0 kernel/workqueue.c:2089
[31200]     0 31200    17601     8230      24       3        0             0 syz-executor1

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.92+ #5
[31201]     0 31201    17634     8477      25       4        0             0 syz-executor1
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
[31210]     0 31210    17700     8240      25       3        0             0 syz-executor2
[31212]     0 31212    17601     8454      25       4        0          1000 syz-executor4
Sending NMI from CPU 0 to CPUs 1:
[31223]     0 31223    17601     8230      24       3        0             0 syz-executor1
NMI backtrace for cpu 1
CPU: 1 PID: 2 Comm: kthreadd Not tainted 4.14.92+ #5
task: ffff8881da9d1780 task.stack: ffff8881da9f0000
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x90 kernel/rcu/update.c:299
RSP: 0000:ffff8881da9f75b8 EFLAGS: 00000083
RAX: 0000000000000001 RBX: 0000000000000046 RCX: ffff8881c95c1eb0
RDX: ffff8881da9d1780 RSI: 0000000000000000 RDI: ffff8881da9d1fac
RBP: ffffffffb08cb1b8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffffb1df3128 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000045043d CR3: 000000011c226004 CR4: 00000000001606a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0x1e6/0x380 kernel/locking/lockdep.c:3990
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152
 console_lock_spinning_enable kernel/printk/printk.c:1577 [inline]
 console_unlock+0x2b9/0xc60 kernel/printk/printk.c:2388
 vprintk_emit+0x128/0x330 kernel/printk/printk.c:1917
 vprintk_func+0x58/0x152 kernel/printk/printk_safe.c:401
 printk+0xba/0xed kernel/printk/printk.c:1990
 dump_tasks mm/oom_kill.c:396 [inline]
 dump_header+0x6d8/0x775 mm/oom_kill.c:428
 oom_kill_process.cold+0x10/0xc29 mm/oom_kill.c:861
Code: 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 0f 8b 93 2c 08 00 00 31 c0 5b 85 d2 0f 94 c0 c3 e8 05 b0 2e 00 eb ea 0f 1f 00 <48> c7 c0 e4 a3 c3 b0 48 ba 00 00 00 00 00 fc ff df 48 89 c1 83 

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/01/11 16:35 android-4.14 fab7352ca8d1 c3f3344c .config console log report ci-android-414-kasan-gce-root
* Struck through repros no longer work on HEAD.